Combined throttle valve and relief valve



March 22, 1932- s. L.- G. KNOX I COMBINED THROTTLE VLVE AND RELIEF VALVE original Filed' Aug. 3. 1927 ATTORNEYS.

Patented Mar.. 22,' 1932 I UNITED- STA-'rss APATENT oFFlcra` SAKUEL L. G. KNOX-Ol' ENGLEWOOD, NIW JERSEY QOHBINED- TK BOTTLE VALVE AND VALVE Original application ald Augusta, 1987, 30.210361.. Divided and thll'vapplioati'on lied ,June

` 1028. Serial No. 288,151.

This application is a division of my co`- pending application, Serial No. 210,261,l filed Au ust 3, 1927.

y invention relates to new and useful 1mf. provements in combined throttle and rehef valves, articularly in double throttle valves ada te to introduce fluid pressure selec.- tivel)y into one of two fluid pressure chests. In connection with the invention shown and described in the co-pending application, it is important that when steam is admitted to one steam chest, there should be substantially no pressure in the other steam chest, and vice versa. Doubtless asimilar need often occurs 1.-. in other types of fluid pressure engine. lIt 1s .the principal object of my present invention to attain this end by the special constructlon of throttle valves shown and described here- 1n.

Further objects and advantages of my inscri tion progresses.

-Tlie invention consists in the novel parts, and in the combinations and arrangements thereof, which are defined in the appended claims, and of which one embodiment is exemplified in the accompanying drawin which are hereinafter particularly descrl ed and explained. l

'lhroughout the description, the same ref-f -erence number is applied to the same member or to similar members.

' Figure 1 is an elevation, partly in sectlon taken on line 1 -1 of Figure 2, of a part of 3? the casting containing the steam chests of a steam engine, which part contains the rocking shaft whereby the motion of the throttle handle is conveyed to the throttle valves.

Figure 2 is a vertical section of a pair of throttle.valves.. It is taken at right angles to Figure 1, on the line 2 2.

Figure 3 is a verticalsection, on an enlargedscale, taken or. line 3 3 of Figure 2. y

Referring to the drawings, it will be seen that 4 is ashaft, rotatable b throttle handle 5. This shaft and` han le control the alternative opening of either valve 6 or valve 7, by the motion of crank pin 8v situated on vthe end of shaft 4. Valve 6 is4l normally 5 0 biased to seat in valve seat 9 by the pressure vention will be readily evident, as the de-` of spring 10 exerted against shoulder 11 of valve 6. Nut 12 is provided for the urpose of y affording access to the mec amsm. Spring 11 bears against this nut. An identically similar arrangement normally biases valve 7 against its seat 13. v

Steam from a source (notv shown) enters the space 14 through the pipe 15. When valve 6 is opened thls lsteam `thnpasses into passage 16 and thence to one I'of the two steam chests (not shown) of the engine in question. This passage and its steam chest will be relferred to as a chamber in the claims.

Similarly the opening of valve 7 admits steam through passage 17 to the other steam chest of the engine.

The valve stem 18 of throttle valve6 has a longitudinal cylindrical bore adapted to re- Y ceive the needle 19. rIfhis needle is a rod of cylindrical shape, flattened at its sides to allowl the passage of steam through the spaces 20. One end 21 of the needle is conical, and is adapted to close a small opening 22 in the valve stem. Openingv 22 connects.

with an aperture 23, which pierces that part 'of the valve stem lying in passage 16. The

other end 24 of the needle 19 projects beyond the end of the valve stem 18, so that the crank pin 8, when rotated toward the valve 6 will come in contact only with this end 24 of the needle 19.

A-similar needle and its associated parts are rovided in the stem ofvalve 7. The. cran pin 8 moves in an open space 25 which communicates with the open air through o pelping 26, and thereby serves as a pressure sin Passage 22 serves as a relief valve to passage 16, as any pressure in passage 16 will .tend to escape through passage 22 at all times except when passage 22 is forcibly closed by the conical end 21 of needle 19.

When handle 5 is rotated to theright in Figure 2, crank .pin 8 will bear on the end 24 of needle 19,`thus closing passage 22; and then forcing the whole valve stem to the right, thus opening throttlevalve 6. When the handle 5 is rotated to the left a similar opening of' valve 7 land closin of its relief valve is elected.- As soon as t e pressure of .10

crank pin 8 on needle 19 is removed, spring 10 closes throttle valve 6, and any accumulated pressure and condensation in passage 16 automatically forces the needle 19 to the left thus permitting the escape of such pressure and condensation through the aperture 23, the passage 22, the spaces 20, space and opening-26.

As the handle 5 is moved from the right to the left the order of these operations is, the closing of the right hand throttle valve, the opening of the right hand relief valve, the closing of the left hand relief valve and the opening of the left hand throttle valve; the reverse order of operation takes place when the handle is moved from the left to the right. This arrangement permits any steam and condensation in passage 16 and 17 to escape to the atmosphere whenever their respective throttle valves 6 and 7 are closed, and therefore prevents any building up of pressure in aoy that steam chest which is not being operated.

Having now particularly described and illustrated one form of my improved valve, I wish to be understood as not limiting myself to the lparticular form exemplied, but rather as availing myself of all equivalents.

I claim:

1. Ina fluid-pressure engine; fluid chambers; throttle valves for controlling admission of fluid to said chambers; relief valves, contained Within the throttle valves for relieving the pressure from said chambers; and means for opening only one of said throttle valves at a time and for closing the relief valve contained Within that throttle valve `which is being opened. Y

2. In a fluid-pressure engine: fluid chambers; two sprin -biased throttle valves for controlling the a ission of fluid to said fluid chambers; a valve stem for each throttle valve; a needle valve associated with each valve stem for relieving Huid pressure in the corresponding fluid chamber, the stems for said needle valves projecting beyond the ends of the valve stems a seat for each needle valve within the corresponding valve stem acontrol member disposed in operative relation to the valvestems, and, when moved in either direction, coacting with the stemV of oneA of the needle valves to force the same against its seat and to move the throttle valve against its spring, thereby first closing the needle valve and then opening the throttle valve.

3.. In a fluid-pressure engine: fluid chamrections for controlling admission of iuid to said fluid chambers, said throttle valves having valve stems, projecting towards each other, and means reciprocable between the ends of said valve stems, for actuating said valve stems'so that only one of the throttle valves is opened at a time.

4. In a fluid-pressure engine: fluid chambers; throttle valves opening in opposite directions for controlling admission of fluid to said fluid chambers', said throttle valves having valve stems projecting towards each other; relief valves contained Within the `bers;throttle valves opening in opposite di- 

